1. Field of the Invention
This invention relates generally to coated fasteners, and more particularly to a method and apparatus for providing a continuous in-line process for mass-producing coated fasteners, such as staples or nails, arranged in a strip or block for ease of handling and packaging as well as loading into a driving tool. A coating is utilized which is composed of 100% dry solids, is virtually free of solvent emissions when applied and during curing and covers substantially the entire exterior surface of each fastener. The coating protects the fastener against corrosion, adheres successive fasteners together into a strip or block and provides improved retention of the fastener when driven into a desired surface.
2. Description of the Related Art
Coating the exterior surfaces of fasteners frequently is desirable to protect fasteners from corrosion. Such coatings also are utilized to adhere a plurality of fasteners together into a strip or block for ease of handling with fastener driving or dispensing devices, such as a staple gun, nail gun or the like.
For example, wire staples or nails frequently are provided successively arranged and secured in a strip. Each strip contains a desired number of staples or nails which are adhered together by the coating and enable easy insertion of the strip within a magazine of a staple or nail gun.
The coating holds the fasteners together in a strip yet is thin enough to enable insertion of the fasteners within the staple or nail gun and allow for separation of the individual fasteners from the strip upon firing of the gun. Such coatings typically are composed of a nitrocellulose resin dissolved in an organic solvent which is applied to the fasteners. After the solvent is evaporated, the coating remains adhered to the fastener. During solvent evaporation, the coating can be utilized to adhere successive fasteners into a strip. An example of such a coating and process is illustrated in U.S. Pat. No. 3,813,985.
Upon evaporation of the solvent in such coatings, however, a large amount of undesirable volatile compounds are emitted. To conform to existing government regulations, the emitted volatile compounds must be contained and properly disposed which adds significant costs to the process.
Additionally, in that patent the individual fasteners first are formed into their desired shapes before coating and adhering them together into strips. This procedure makes it difficult to handle the individual fasteners and arrange them as required for processing.
It therefore would be desirable to provide a method and apparatus for mass-producing coated fasteners which utilizes a coating composed of 100% dry solids and is virtually free of solvent emissions when applied and during curing where substantially the entire exterior surface of each fastener is provided with the coating. The coating serves to protect the fastener from corrosion, adhere successive fasteners together into a strip and provide increased retention when the fastener is driven into a surface.